Metal seals for weld-deformed high temperature pneumatic ducting joints

Abstract

A single-ply sheet metal seal ring with a convoluted, V/E-shaped cross-section having planar-circumferential flexibility is shown to be more capable of conforming to the sealing face contours of warped, weld-deformed flanges than thin layer, multiple-ply seals developed to replace earlier E-shaped seals for this purpose. The basis of the improved flexibility of the new seal lies mainly in the discovery of geometric relationships that permit a reduction in the thickness of the sheet material employed in the construction of the seal while maintaining its pressure containing capabilities.

1. A seal for sealing when positioned within a groove in a compressed state comprising:
 a cross-section with a central axis; 
 a center curved region extending symmetrically across said central axis; 
 a pair of central legs, each central leg having a first end connected to opposing ends of said center curved region and a second end connected to a first end of a heel, said central legs angling inwards from said center curved region towards said central axis to form a bulbous-shaped center curved region; 
 a pair of opposing outer legs, each outer leg connected to a second end of said heel and extending outwards from said heel and from said central axis sufficient for said outer legs to contact opposite surfaces of said groove in which said seal is placed and forming a V-shape to said cross-section outer dimensions, each of said opposing outer legs including an inflection region curving inwards towards said central axis leg end portion opposite said heel that forms an angle to said central axis sufficient for opposing leg end portions to span said groove in which said seal is placed without having said outer leg inflection region come in contact with said central leg when said seal is in said compressed state, said pair of opposing outer legs connected at said heel to form a narrow portion of said V-shape such that the outer legs at the heel cannot contact said groove; and 
 an inwardly terminating curved portion on each of said outwardly angled opposing outer legs; 
 wherein said center curved region extends along said central axis a greater distance than the projection of said outer legs on said central axis; and 
 wherein the central legs angle inward sufficient to allow each outer leg to contact the groove at only one point. 
 
     
     
       2. The seal of  claim 1  wherein said seal comprises a single-ply construction of resilient metal. 
     
     
       3. The seal of  claim 1  wherein said seal comprises an integral piece of resilient metal in a ring shape. 
     
     
       4. The seal of  claim 1  wherein said center curved region bulbous shape is formed by adjoining central legs, and has a circumferential curvature greater than 180 degrees to angle said central legs second end inwards towards each other without contacting each other. 
     
     
       5. The seal of  claim 1  wherein said outer leg inflection regions are located approximately midpoint of each of said leg region. 
     
     
       6. The seal of  claim 1  wherein said heel circumferential curvature angle is less than said center curved region circumferential curvature angle. 
     
     
       7. The seal of  claim 1  wherein each of said outer leg defines a V-shaped gap with said adjacent central leg so that when said seal is in a compressed state, said outer leg inflection regions do not contact said adjacent central leg. 
     
     
       8. The seal of  claim 1  wherein said inwardly terminating curved portion includes a sinuous configuration of a convex section and a concave section. 
     
     
       9. The combination of the seal of  claim 1  with a pair of relatively movable flange members which define between them a cavity in which high pressures and temperatures are encountered while said flange members are moved into engagement. 
     
     
       10. A sealing ring for sealing within a groove comprising:
 an integral piece of resilient metal, approximately E-shaped in radial cross-section about a central axis; 
 inner legs symmetric about said central axis joined at a bottom end to a curved bottom section having a circumferential curvature of greater than 180 degrees such that said inner legs flare towards said central axis, each of said inner legs terminating in separate curved heel sections at a second end; 
 said heel sections having a circumferential curvature less than said curved bottom section; 
 outward legs each having an inflection region curved towards said central axis and attached to respective heel sections such that said outward legs flare outwards relative to said central axis, said outer legs at the heel substantially narrower than where said outer legs flare outwards, such that said outer legs at the heel cannot contact said groove; and 
 a curved end section on each of said outward legs curved in a direction opposite said inflection region towards said central axis; 
 wherein said center curved region extends along said central axis a greater distance than the projection of said outer legs on said central axis; and 
 wherein the central legs angle inward sufficient to allow each outer leg to contact the groove at only one point; 
 said seal ring forming a seal in a compressed state in such a manner that said inner legs and said outer legs do not touch when said seal is compressed between movable flange members which define between them a cavity when said flange members are moved into engagement. 
 
     
     
       11. The seal of  claim 10  wherein said seal comprises a single-ply construction. 
     
     
       12. The seal of  claim 10  wherein said outer leg inflection regions are located approximately midpoint of each of said leg region. 
     
     
       13. The seal of  claim 10  wherein said curved end sections include a sinuous configuration of a convex section and a concave section.